Applied ethics takes a theory of ethics, such as utilitarianism, social contract theory, or deontology, and applies its major principles to a particular set of circumstances. Typical examples include applied fields such as medical ethics, legal ethics, environmental ethics, corporate social responsibility, or business ethics.

The chief difficulty with formal, applied ethics is the potential for disagreement over what constitutes the proper theory or principles to apply, which is bound to result in solutions to specific problems that are not universally acceptable to all participants. For example, a strict deontological approach would never permit us to deceive a patient about his condition, whereas a utilitarian approach would have us consider the consequences of doing so. A deontologist will often come up with a very different solution than would a utilitarian, given the same facts.

One modern approach attempting to address this is casuistry. Casuistry attempts to establish a plan of action to respond to particular facts - a form of case-based reasoning. By doing so in advance of actual investigation of the facts, it can reduce influence of interest groups. By focusing on action and not the rationale, it can reduce influence of prior bodies of precedent and explicit moral codes.

See also: ethics, ethical codes, arbitration, etiquette, list of ethics topics